Computing system



P 9 l. E. GROSDOFF 2,521,787

COMPUTING SYSTEM Filed March 30, 1944 lllllll lm..

Zhwentor Earl: 6 95% attorney Patented Sept. 12, 1950 Igor Gro sdoihPrinceton, NHL, -as signor to Radio Corporation of America, a corporation of Delaware Application March so, 1944, Serial No. 52s,721

6 Claims. 1 (01. 235-92).

This invention relates to computing systems i of the electronic type, and has for;its principal object the provision of an improved apparatus and method of operation whereby a number-ofelectric pulses maybe counted with less appara tusthan that heretofore required for the purpose.

A further object is the provision of means whereby an indication is produced only when a me determined number of such pulses have been registered.

The illustrated form of the invention includes a number of trigger circuit units connected in a closed loop and a single trigger circuit which is separate from this loop. The pulses to be I counted are applied both to the single trigger the closed loop. Each trigger circuit in theloop has associated with it a pair of indicators, such as neon lamps or the like. l. The single trigger circuit functions in response to the applied pulses to select one or the-other lamp of a pair of the indicators. The trigger circuits of the loop operate successively to register the applied pulseson the selected indicator:

Connected between the single trigger circuit and the loop is an output tube provided with two control grids, so connected that they 'botlr receive positive pulses simultaneously only when which current fiows in the various trigger cirpulses have been registered on all the indicators, each trigger circuit in the loop having been utilized to register two pulses' Thus .the circuit.

may include, for examplaa loop containin five" trigger-circuits which register the first five pulses successively on the first indicator of each pair and the second five pulses on the second indicator of each pair.

invention has been applied;

tion with' the accompanying drawing, and its scope is indicated by the appended claims,

The single figure of the drawing is a wiring diagram of a computing system to which the This systemvincludes ,a, plurality of trigger circuits H to l5, which are connected through a lead It to form a closed loop. Connected to the right anode of each trigger circuitv is a pair -of indicator lamps 5-40, l-6, 2-1, 3-8 and.

49. Potential is applied tothese indicator lamp from a trigger circuit ll througha duo diode I circuit and to the trigger circuits connected in:

I8. An output tubel9 has ,onecontrol grid which is coupled through a capacitor 2| to the left anode of. the trigger circuit, and another control grid 22 which is coupled through a capacitor 23 to the left anode of the trigger circuit IL Potential for operation of the trigger circuits and the output tube is applied between the terminals 24 and'25, the latter of which is grounded and connected to the various cathodes. From a terminal 26, a negative bias potential is applied to the left grids of the trigger circuits I1 and H, to the right grids of the trigger circuits l2, l3, l4 and I5, and to both grids of the out-v Only in response to the application of "ten pulses, or some multipl of ten pulses, are both grids of the output tube simultaneously at a' positive potential. When this happens, a pulse is' delivered to an output lead connected to the anode of the output tube. more'or fewer trigger circuits may be connected in the closed loop and that the single trig er circuit'may be replaced by a plurality of trigger" put or control tube IS. A reset switch is normally closed to apply negative bias potential to other grids of the various trigger circuits and is opened to establish a standby condition under cuits, as indicated by arrows. The pulses to be counted are applied to a terminal 28 and every tenth of these pulses is delivered at a terminal 29.

Assuming a standby condition to have been .established by opening and closing the switch 30 with the current of the trigger circuits, as in dicated by arrows both grids of the tube G9 are at a negative potential sufficient. to ,makethe tube nonconductive unless both grids receive a It is apparent that I} circuits connected in a closed loop, depending on the character of indication desired.

The expression closed loop is used hereinafter to designate a circuitin which a plurality; of trigger circuit units, or the equivalent are each similarly coupled to two other trigger circuit units to. form a closed loop.

The invention will be better understoodfrom the following description considered in connec' positive signal; the left anode of the duo, diode. I8 is then at a relativelyhigh potential; the lamp I0 is lighted; the lamps l to BMareun lighted, because their lower terminals are at sub- 'stantially the same potential as the bus connected to the terminal 24; and the lamp 5 is unlighted, because the right anode of the duo diode I8 is at a relatively minus potential.

The application of a negative puls jto the ter 'minal 28 transfers current conductivity fromthe right to the left side of the trigger circuit units": l1 and 1 II and from-the leftto the right side of unit '12. Underth'e'se, conditions, both gridsof thefo 'itput tnbe 1,9 are more negativejthe 3 hand anode of the duo diode I8 is more positive, and the lamp I is lighted. Lamps 5, 1, 3 and 9 also connected to the same diode as the lamp 1 and lamps l0, 6, 2, 8 and 4 connected to the other diode are. not lighted for the reason that the left hand sides of the units H, I3, l4 and [5 are conducting current. In turnin over, unit H appliesfa positive pulse to the right grid of unit I2, thus transferring current from its left to its right anode and unit i 2 then becomes sensitive to the next negative pulse from the lead 28 to be turned back to its standby condi= tion. Consider lamps in, 2, 8 and 4, which are connected between positive anodes and the left;

cathode of double diode l8. They 'do not light even though the left anode of trigger circuit IT is positive, because the left d'iode o'i, [8 cannot conduct a current in a reverse direction. a

The application of a second pulse to the termi nal 28 transfers current to the right side of the unit 11'; to the left sidebfithe -uni't' 'l2; audvo=- the right side of unit 13. The result-'isthat the left anode of I! and the output tubegr-id zi are more positive'a'nd the'lamp-Z is-lighte'd.

A third pulse applied to tne tennmal zanausfers current to thel'eftside df 'thefiinitsHl and l3 and to the right side of th'e unifiM; result-- ing in' the lighting or thEIamp S.

The lamps 4' to were similarly lighted; one" after another, in response to' the appli'caltion fof successive pulses to the terminal 28: Oniy whelr the tenthpulse' is applied are both control grids I 20 and 22'of-the' output-tube 19' subjectedt apositive pulse, thus permitting the t'ube Hl to' take current and applying the outputterminalfll' a The various steps in the operation of theisystem are readily ascertained from the following tabulation which is"self eXpla-natory': I

' Unit Unit Unit Unit Pulse Unit harap 14 0.11 1

Standby The basic fe'atures of the present inventionare asnegative pulse to a plurality of trigger circuitsconnected? in a closed loop, separate trigger circuit means which may consist of one or more trigger circuits; and

means connected between the loop and separate trigger circuit means for delivering an output pulse in response to a number of appliedpulse's which is a multiple of the number of trigger cire cuits in the loop.

I claim as my invention: V v

1. The combination of' a plurality of trigger circuits each including-a pair of electron di's-' charge elements havingtheir grids each cross: connected to the anode of the other so' thatcurrent conduction is stable in either one' or the other, of said elements, terminals for simultane ously applying input pulses to all'of' said trigger:

circuits, means interconnecting some. of said trigger circuits so that their current conductive;

conditions are successively changed in response" 4 to the application of said input pulses, and an electron discharge element having at least two grid electrodes, said electron discharge element having one grid connected to one of said interconnected trigger circuits and another grid connected to one of the electron discharge elements of the other of said trigger circuits to deliver an output pulse in response to a predetermined current conductive condition of said trigger circuits to which said electron discharge element grids are connected 2. The combination of a plurality of trigger circuits each including a pair of electron discharge elements having their grids each crossconnected to the anode of the other so that current conduction is stable in either one or the other of saidele'ments, terminals for simultaneously applying input pulses to all of said trigger circuits, means interconnecting some of said trigger circuits so that their current conductive conditions are successively changed in response to'the application of said input pulses, a plurality of pairs of indicators, means connecting said in'- dic'ator pairs each to the anode of an electron discharge element of a different one of said interconnected trigger circuits, and means including the other of said trigger circuits for selecting said indicators one after the other in responsef to said input pulses.

3. The combination of a plurality of'trigger' circuits each including a pair of electron discharge elements having their grids each crossconnectedto the anode of the other so thatcur-- rent conduction is stable in either one or the other, of said elements, terminals for siinultane ouslyapplying input pulses to all of said trigg'e1" circuits, means interconnecting all but one" of said trigger circuits so that their current--con'-" ductive conditions are successively changed in response to the application of said input pulses,

an electron discharge'elernent having-at least two grids, one of said grid's'being coupled to one" of the electron discharge elements of one of said interconnected trigger circuits, the'other of trigger circuits.

4. The combination of a plurality of trigger circuits each including a pair of electron dis charge elements having their grids each crossconnected to the anode of the'otherso'thatcur rent conduction is stable in either one or the other of said elements, terminals for s'imultane-wously applying input pulses to all of said trigger circuits, means interconnecting some of said trigger circuits so that their current conductive; conditions are successively changed in response; to the application-of said input pulses, a plural ity of pairs of indicators, means connecting-said. indicator pairs each to-the anode of-anelectronv discharge element of a different one of said interconnected trigger circuits, and means including the other of said trigger circuits for selecting said indicators one after the other in res'p'onse'to said input pulses and means responsive to the cori ductive-conditions of said trigger circuits for delivering an output pulse only in response to, input pulses of a numberwhich is twice that of" of indicators connected to the anode of a single triode of the first of said trigger circuits, and a pair of diodes each connected between a different one of said indicators and the anode of a different triode of said second trigger circuit.

6. The combination of first and second trigger circuits each including a pair of triodes having their grids each cross-connected to the anode of the other so that current conduction is stable in either one or the other of said triodes, a pair of indicators connected to the anode of a single triode of the first of said trigger circuits, a pair of diodes each connected between a different one of said indicators and the anode of a difierent triode ofsaid second trigger circuit, and means connected between an anode of the first of said trigger circuits and an anode of the second of said trigger circuits for delivering a pulse in response to both of the anodes interconnected through said means becoming non-conductive.

IGOR GROSDOFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,158,285 Koch May 16, 1939 2,272,070 Reeves Feb. 3, 1942 2,306,386 Hollywood Dec. 29, 1942 2,404,047 Flory et a1. July 16, 1946 2,405,664 Mumma Aug. 13, 1946 2,410,156 Flory Oct. 29, 1946 2,422,698 Miller June 24, 1947 FOREIGN PATENTS Number Country Date 355,705 Great Britain Aug. 24, 1931 

